As of November 29th, Sun has changed its availability policy for patches and updates for Solaris 10:

Sun is announcing changes to how we will be providing access to Solaris 10 patches, or what we now call software updates. Now that Solaris 10 is freely available, support services require the purchase of a Sun Service Plan.
Under this new policy, access to patches, or what we now call Software Updates, is restricted. Security fixes and hardware driver updates are publicly available for free, but access to all other patches requires a Sun Service Plan.

As of December 2nd, I can’t even download software updates/patches *with* a Sunsolve login (“file not found” errors).